油田6kV无人值守变电站经济改造

变电站无人值守是变电站未来发展方向,通过新技术、新设备的应用,变电站微机设备可以实现故障信号远传、远方遥控分合闸、远方电流电压电量数据的实时采集,由此,无人值守变电站的设备基础已达到要求,本文通过对现有变电站的情况分析,对变电站无人值守应用进行一些个人的探讨及理解。

The Nucleosides Contents and Their Variation in Natural Cordyceps sinensis and Cultured Cordyceps Mycelia

Aim: To compare the contents of nucleosides from natural Cordyceps sinensis and cultured Cordyceps mycelia, and to study the effect of humidity and heat on the content of nucleosides. Methods: The contents of nucleosides were determined by using high performance capillary electrophoresis (HPCE). Beckman P/ACE System 5010 apparatus equipped with a UV detector and a Beckman untreated fused-silica capillary (57 cm 75 mm, 50 cm effective length) was used. Before sample injection, the capillary was rinsed with 1 molL-1 sodium hydroxide solution and running buffer for 5 min, respectively. A voltage of 20 kV was applied for the separation. Pressure injection was 586 kPa for 6 seconds, and the wavelength of detector was 254 nm. The running time was 20 min at 20 oC. The effect of humidity and heat on the contents of nucleosides from natural Cordyceps sinensis and cultured Cordyceps mycelia was observed for 1, 3, 5 and 10 days at temperature 40 oC, and relative humidity 75%. Results: The content of nucleosides from natural Cordyceps sinensis was higher than that from cultured Cordyceps mycelia. But the contents of nucleosides from freshly collected natural Cordyceps sinensis were very low, even below the limit of quantitation. The contents of nucleosides from natural Cordyceps sinensis were significantly increased by humidity and heat, but this phenomenon was not observed in cultured Cordyceps mycelia. Conclusion: There are differences between the nucleosides from natural Cordyceps sinensis and cultured Cordyceps mycelia. The nucleosides in natural Cordyceps sinensis may be derived from the degradation of nucleic acids. This implies that adenosine being used for the quality control of natural Cordyceps sinensis may have to be reconsidered.

工控系统模拟输入模块转换误差分析及修正

为解决施工现场对工控系统模拟量回路的修正问题,研究了使用1台过程校验仪和1张定制的Excel表格完成工业控制系统模拟输入模块通道的性能判断和采集值修正的方法和流程。首先,搭建实验专用平台,即仿真工控系统中直流电流信号的工作电路;然后,计算模拟输入模块的出厂误差,记录标准电流和实际采集值的对应关系,判断模拟输入通道的性能;最后,将计算过程输入到Excel表格中,验证修正公式。实验结果表明,相比实际采集输入,经过修正后的转换误差明显变小,比较方便地解决了现场调试阶段模拟输入模块转化误差的分析和修正。

高炉大修施工监测实施方法研究及应用

本文通过研究分析高炉大修过程中应力、变形等参数的各种监测方法,将采集值与报警值进行校核,并将结果及时反馈给施工单位和设计单位,有效满足了高炉大修安全施工和信息化施工管理的需要,可为今后相关的工程建设项目提供经验参考。

基于MSP430的微弱信号检测系统设计与实现

为了克服微弱信号检测难度大、精确度低,实现强噪声环境下微弱信号的准确、快速检测,根据锁相环检测原理,设计了基于TI公司超低功耗微控制器MSP430G2553的微弱信号检测系统。该系统由加法器、纯电阻分压网络、微弱信号检测电路、显示电路组成,用来检测在强噪声背景下已知频率的微弱正弦波信号的幅度值,并数字显示出该幅度值。微弱信号检测电路分为测量放大电路、滤波电路、乘法检波电路和低通滤波电路,将微弱的小信号提取出并检测其幅值。整个系统功耗低、检测精度高、成本低。电路结构简单,利于在便携设备中使用。通过实验表明,设计的微弱信号检测系统扩大了噪声信号幅度的范围,提高了检测精度,整体性能提高了5%以上,同时保持使误差在5%以下。

基于机器视觉的车道线在线识别系统设计

针对目前车道线识别系统因处理对象为离线图像或视频文件而难以实现车道线在线识别的问题,大多数车道线识别算法为了减少图像处理运行量,通常选取固定的兴趣区域(region of interest,ROI)进行处理,导致难以适应环境的动态变化且存在不同程度的识别误差。为此,提出了一种基于机器视觉的不设定兴趣区域的车道线在线识别系统。首先,利用VBAI(Vision Builder for Automation Inspection)平台对实时采集的彩色道路图像进行预处理,完成彩色图像的灰度化、滤波及二值化处理。然后,建立图像坐标系,并构建多条向外发散的灰度值采集线,灰度值采集线与车道线相交处的灰度值会发生较大改变,当某点的灰度值高于设定的灰度阈值时,记该点为边缘突变点。接着,借助直线拟合算法对所有车道边缘突变点进行拟合以完成车道线识别,并求解两侧内车道线的远方消失交点坐标和车辆行驶偏离车道中心线的相对航偏角,当相对航偏角超过不同等级的安全阈值时,系统人机交互界面的提示框呈现不同的颜色以进行提醒或预警。最后,借助LabVIEW进行API(application programming interface,应用程序接口)脚本调用,实现图像处理程序的连续运行与车道线在线识别。试验结果表明,所提出的车道线在线识别系统的识别准确率达98.41%以上,相对航偏角的测量误差小于0.056°,图像处理速度达42帧/s以上,兼具识别的准确性与实时性。综上可知,基于机器视觉的车道线在线识别系统可有效识别出不同环境路面的车道线,并实现行驶偏离预警,可将其应用于基于自动驾驶技术的车道保持辅助(lane keeping assist,LKA)系统。

Dual-channel Method for Fast Long PN-code Acquisition

Long PN-code acquisition is a difficult and time-consuming task due to long code period.To accelerate acquisition,folding methods like XFAST are widely used.In highdynamic environment however,the application of those methods are largely restricted due to nonnegligible residual frequency.This paper proposes a new dual-channel method for fast acquisition of long PN-code.In the proposed method,both non-overlapping local PNcode blocks are employed to correlate with input sample block;the detection process is eased through finding the maximum value among correlation results and verification is made with all the full and partial peaks taken into account.False alarm probabilities from analysis of the verification process are derived.Both theoretical and Monte Carlo simulations reveal that,with respect to acquisition probability and mean acquisition time under the same false alarm rate,dual-channel method has advantage over zero-padding and XFAST based folding methods under certain false alarm probabilities.

Comparative Analysis of EEG Signals Based on Complexity Measure

The aim of this study is to identify the functions and states of the brains according to the values of the complexity measure of the EEG signals. The EEG signals of 30 normal samples and 30 patient samples are collected. Based on the preprocessing for the raw data, a computational program for complexity measure is compiled and the complexity measures of all samples are calculated. The mean value and standard error of complexity measure of control group is as 0.33 and 0.10, and the normal group is as 0.53 and 0.08. When the confidence degree is 0.05, the confidence interval of the normal population mean of complexity measures for the control group is (0.2871,0.3652), and (0.4944,0.5552) for the normal group. The statistic results show that the normal samples and patient samples can be clearly distinguished by the value of measures. In clinical medicine, the results can be used to be a reference to evaluate the function or state, to diagnose disease, to monitor the rehabilitation progress of the brain.